Optoelectronic components on an organic basis, for example organic light emitting diodes (OLEDs) are being increasingly widely used in general lighting, for example as a surface light source, or for representing information for example as a sign.
An organic optoelectronic component, for example an OLED, may include an anode and a cathode with an organic functional layer system therebetween. The organic functional layer system may include one or a plurality of emitter layer(s) in which electromagnetic radiation is generated, one or a plurality of charge generating layer structure(s) each composed of two or more charge generating layers (CGL) for charge generation, and one or a plurality of electron blocking layer(s), also designated as hole transport layer(s) (HTL), and one or a plurality of hole blocking layer(s), also designated as electron transport layer(s) (ETL), in order to direct the current flow. In one conventional method, a metallization is applied on a glass substrate and the electrodes of the OLED are electrically contacted by means of the metallization. The metallization is conventionally formed as an electrical busbar and/or contact pads. The metallization can conventionally be optically inactive, i.e. emit no light. Furthermore, as encapsulation, a glass cover is laminated and/or a thin-film encapsulation is deposited onto the electrode on the organic functional layer system, for example by of chemical vapor deposition (CVD) or atomic layer deposition (ALD).
In a conventional OLED, the laminated glass cover, the metallization, for example in the form of contact pads; the cathode and/or the anode can have a different transmissivity for electromagnetic radiation. As a result, conventional transparent OLEDs, on account of the laminated glass cover for encapsulation and the metallization for electrical contacting, can have lateral variations in at least one optical variable, for example the transmission, absorption and/or reflection of electromagnetic radiation. As a result, electromagnetic radiation incident on the transparent OLED is reflected, transmitted and/or absorbed differently in the region of the metallization, for example, than in the light emitting region of the OLED. By means of this variation, information to be represented can be altered undesirably, for example in the case of an optoelectronic component in the form of a sign.
Furthermore, individual regions of a conventional optoelectronic component can absorb electromagnetic radiation to different extents. As a result, the individual regions can heat up differently and, for example, thermal strains and/or thermoelectric voltages can be generated in the optoelectronic component.
Hitherto, OLEDs have been produced with metallic contact pads outside the optically active region, that is to say in the optically inactive region, in order to ensure the external contacting of the anode and cathode. Alternatively, a combination of indium tin oxide and a metallic layer has also been used hitherto. The metallic contacts also serve for current distribution outside the OLED in order that the anode and/or the cathode are/is supplied with current uniformly. In conventional components, a metallic layer is always used for current distribution in order to supply the anode with current uniformly.